Articles by James P. Grant in JoVE
Simulation, Fabrication and Characterization of THz Metamaterial Absorbers James P. Grant1, Iain J.H. McCrindle1, David R.S. Cumming1 1School of Engineering, University of Glasgow This protocol outlines the simulation, fabrication and characterization of THz metamaterial absorbers. Such absorbers, when coupled with an appropriate sensor, have applications in THz imaging and spectroscopy.
Other articles by James P. Grant on PubMed
Imprinted Terahertz Artificial Dielectric Quarter Wave Plates Optics Express. Jun, 2010 | Pubmed ID: 20588340 We have developed low-loss polymer artificial dielectric quarter wave plates (QWP) operating at 2.6, 3.2 and 3.8 THz. The QWPs are imprinted on high density polyethylene (HDPE) using silicon masters. The grating period for the quarter wave plates is 60 microm. 330 microm, 280 microm and 230 microm deep gratings are used to obtain a pi/2 phase retardance between TE and TM polarization propagating through the QWPs. High frequency structure simulator (HFSS) was used to optimize the grating depth. Since the required grating depth is high, two plates, fixed in a back-to-back configuration were used for each QWP. A maximum aspect ratio (grating height/grating width) of 6.6 was used.
Method for Vector Characterization of Polar Liquids Using Frequency-domain Spectroscopy Optics Letters. Sep, 2011 | Pubmed ID: 21886200 A device for performing vector transmission spectroscopy on aqueous and polar solvent specimens at terahertz frequencies is presented. The device enables the direct measurement of the complex dielectric function across the terahertz band using a Fourier transform IR spectrometer for lossy solutions. Using microfluidic sampling, specimen handling is straightforward and direct measurements on polar specimens are made possible. The method is scalable to longer or shorter wavelengths.
Application of Terahertz Spectroscopy to the Characterization of Biological Samples Using Birefringence Silicon Grating Journal of Biomedical Optics. Jun, 2012 | Pubmed ID: 22734784 We present a device and method for performing vector transmission spectroscopy on biological specimens at terahertz (THz) frequencies. The device consists of artificial dielectric birefringence obtained from silicon microfluidic grating structures. The device can measure the complex dielectric function of a liquid, across a wide THz band of 2 to 5.5 THz, using a Fourier transform infrared spectrometer. Measurement data from a range of liquid specimens, including sucrose, salmon deoxyribonucleic acid (DNA), herring DNA, and bovine serum albumin protein solution in water are presented. The specimen handling is simple, using a microfluidic channel. The transmission through the device is improved significantly and thus the measurement accuracy and bandwidth are increased.